The field of the invention embraces a handle-mounted, hand-manipulated power driven rotary head spinning at high speed on a vertical axis with one or more flexible lines, usually made of nylon, radially distended centrifugally from said head to very effectively trim vegetation particularly in lawn edging.
Various expedients have been brought out for facilitating the replenishing of the working free line end portions as these wear from use. These all provide a reserve supply of line wound on one or more spools rotatably confined in the head but normally locked against rotation. Each expedient offers a different mechanism aiming to make it easier for the operator to replenish the working cutting line end portions but none of these expedients has as yet proven entirely satisfactory.